Machine for grinding bits



' Sept. 18, ;945. F, DIXON 2,384,899

MACHINE FOR GRINDING BITS Filed Feb. 23, 1944 3 Sheets-Sheet l Sept. 18, 1945. F. DIXON MACHINE FOR GRINDING BITS 3 Sheets-Sheet 2 Filed Feb. 25, 1944 Sept. 18, 1945. F. DIXON MACHINE FOR GRINDING BITS Filed Feb; 23, 1944 3 Sheets-:Sheet 3 I Patented Sept. 18, 1945 UNlTEDiSTATE PATENTQoFFIC-E:

MACHINE FoR GRINDING BITS Fate Dixon, Durham, N. 0., assignor of one-half to Arthur L. Walton, Durham, N. G.

Application February 23, 1944, Serial No'.'523, 590 M I 5 Claims. My invention relates to a machine for grinding bits or the like. a

An important object of the invention is to provide a machine of the above mentioned character which will properly grind the face of the bit with of this application, and in which like numerals are employed to designate like parts throughout the same,

Figure l is a perspective View of a bit grinding,

machine embodying my invention, Figure 2 is a plan viewof same,

Figure 3 is a sideelevation of same,

Figure 4 is a vertical section taken on line. 4-4 of Figure 2, W e

Figure 5 is a similar view taken on line 5-5 of Figure 2,

Figure 6 is a similar view taken on line 6-6 of FigureZ, parts inelevation,

Figure '1 isa horizontal section taken on line 1-1 of Figure 3, i

Figure 8 is a fragmentary plan view of the grinding wheel and bit,

Figure 9 is an end elevation ofthe bit-holding frame,

Figure 10 is a vertical longitudinal section taken on line Ill-I0 of Figure 9, and,

Figure 11 is an exploded perspective view of the motor holding frame and associated elements.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral I0 designates a base, having a vertical post I l rigidly secured thereto. The numeral [2 designates a motor holder or frame, including a horizontal bar l3, having a central opening I 4, for receiving the upper end of the post l I The horizontal bar I 3 is clamped to the post H by a setscrew I5. Rigidly secured to the ends of the horizontal bar l3 are vertical arms l6,

connected at their upper ends by a curved horizontal strap I1. The curved strap I1 is concentric with the post H. The numeral l8 designates a vertically arranged motor, resting upon the horizontal bar. l3 and attached to the curved strap IT by bolts I9 orthe like. The motor is therefore concentric with the post II and is supported the grinding wheel upon thereby. The motor l8 has a vertical armature shaft 20, to the upper end of which is secured a grinding wheel 2|, rotated in a horizontal plane. Any suitable means may be employed to mount the armature shaft 20 for rotation therewith. I

The numeral 22 designates a horizontal arm, extending radially of the grinding wheel 2| and having an opening 23 to receive the post I l. The end of the arm 22 adjacent to the opening 23 is preferably split, so that the arm may be clamped to the post H by a bolt 24. The bar or base l3 preferably rests upon the horizontal arm22.

' The arm 22 is provided near its outeror free end with a vertical opening 25, to receive a shank 26, dependingfrom a socket 21, and formed integral therewith. The shank 26 has a longitudinal groove 28, for receiving the end of a setscrew 29, having screw threaded engagement with the arm 22, at 30. It is thus seen that by slightly unscrewing the setscrew 29 the shank 26 may be raised,

but the setscrew 29 projecting into the groove 28 will hold the stem 26 against turning upon its longitudinal axis, andafter this the setscrew 29 is manipulated to clamp the stem 26 at the raised elevation. The shank 26 may be vertically ad justed, depending upon the width of the grinding wheel 2L The socket 21 has a cylindrical recess 3|, to rotatablyreceive a cylindrical extension or portion 32 of a vertical post or arm .33. The extension 32 is adapted to be turned upon its longitudinal axis within the recess .3! and to be clamped to the socket 21 in the selected adjusted position by a setscrew 34. The verticalpost. or arm l3 has a tapered annular portion 35, equipped with a scale 36, for co-action with a stationary pointer. 31. formed upon the top of the socket 21. This scale and pointer indicate the extent of turning movement of the post or arm 332w Preferably formed integral withthe vertical arm or post 33 is a head 38, provided upon one face with a horizontal dove-tailed groove or recess 39, receiving a horizontally adjustable slide or carriage 40. This slide or carriage is engaged. by balls 4|, forced inwardly by adjustable screws 42, engaging within screw threaded openings 43. By the adjustment of the screws 42 the play between the slide or carriage 43 and the head 38 may be taken up. The slide or carriage is' longitudinally adjusted by an annular flange or ring 44, operating within a transverse groove 45, formed in one face of the slide or carriage 40, near its outer end. The annular flange or ring 44 is rigidly mounted upon a bolt 46, having screw threaded'engagement within an opening 41, formed in the head 38. The bolt 46 has a milled head for turning it. It is thus seen that when bolt 46 is turned the slide or carriage 40 will move longitudinally with respect to the head 38.

The slide or carriage 40 is provided near its inner end with a transverse horizontal opening 49, to pivotally receive a cylindrical shank 50, having a head or block rigidly secured thereto. This head orblock has an opening'52 formed therein. The shank 50 has an annular groove 53, receiving the rounded end 54 of a setscrew 55. The shank 50 is therefore pivotally mounted upon the slide or carriage 46 to turn in a :ver-" tical plane. The numeral .56 designates a swinging carrier. having a recess 51 to receive the head or block 5|, and openings 58 for alignment with the opening 52 for receivinga pinor pivot 59. The carrier 56 therefore swings upon the head 5| at a right angle to the turning movement of the head 5| with respect to the slide or carriage 46. The carrier 56 has a limited swinging movement with respect to the head 5|, which is slightlyspaced from the end wall of the recess 51. The carrier 56 has a tail or extension 66, preferably integral therewith, arranged to engag-e beneath an adjustable Vertical stop or bolt 6|, having screw-threaded engagement within an opening 62 formed in a head 63, carrying a screw threaded shank 64, engaging in a screwthreaded opening 65 formed in the slide or carriage 40. The head or block 63 is therefore rigidly attached to the slide or carriage. V

The holder for the bit 66 includes a channellever 61, formedV-shaped in cross section. This channel lever has'a slide 68 to be clamped in the selected adjusted position by a bolt 65! extending through a longitudinal slot 10. The channel lever 6.1 receives the bit 66, as shown. Preferably formed integral with the channel lever 61 near its inner end is a loop or frame 1|, arranged at a right angle with relation thereto. Arranged within this loop .Or frame is a jaw 12,- carried by .aslide 13, for clamping engagement with the bit 66. The slide 13 has a swiveled connection witha feed screw 14, having screw threaded engagement with the end of the loop or frame 193 and having a milled head for turning the same. Preferably formed integral with one side of the frame or loop 1! is a block or lug 16,- having a longitudinal opening 11 for slidably receiving .a gage .or index element 18, adapted to be clamped in the selected adjusted position by a setscrew 19 having screw-threaded engagement with the block 16, as shown. The gage has a finger 8,0 to engage the drill 66, as shown. Rigidly attached to the side of the loop or frame 7| adjacent to the block 16 and near the inner end ofthe loop or frame 1| is a cylindrical stud 8|, pivotally mounted in a transverse horizontal opening 82 formed in the carrier 56, and clamped to the carrier by a set screw 83. The stud 8| may be turned with respect to the carrier 56 but is ordinarily locked to the carrier. The axis of the stud 8| is at a right angle to the plane of movement of the carrier 56, while the longitudinal axis of the loop orframe 1| is vertically inclined in a plane at a right angle to the plane of movement of the carrier. The frame or loop 1| is arranged in the transverse plane extending generally at a right angle to the plane of movement of the carrier 56, but the loop or frame 1| may be angularly adjusted longitudinally of the carrier 56, by turning the stud 8| within the opening 82.

The bit 66 has beveled faces 66 which are hollow ground by my machine.

The operation of the machine is as follows: The channel-lever 61 has its outer end swung to the right, Figure 2, whereby the inner end of the carrier 56 and the bit 66 is swung toward the slide or carriage 40 and the grinding wheel 2|, and the face 66 of the bit may engage the periphery of the grindingwheel. The arm or post 33 is now turned upon its longitudinal axis, for determining the'angle of the bevel face 66 and this angle is indicated by the pointer 31 upon the scale 36. The post 33 is now clamped in the selected adjusted position. The drill 66 is clamped in the channel lever 61, and the gage 18 engages the drill, as shown. When the outer end of the channel lever 61 is in position, the tail 60 of the carrier 56 will engage the stop 6|, and the face 66 of the bit will engage the periphery of the grinding wheel 2| adjacent to the lower end of the grinding wheel. The outer end of the channel-lever 61 is held to the right andis then swung downwardly about the pivot, 56, whereby the face 66 of the'bit engages the rotating grinding wheel as such face swings upwardly and disengages the grinding wheel during the upward portion of such swinging movement. When the forward end of the channel-lever 61'has reached the uppermost position, the outer end of the channel-lever is swung to the left, which shifts the inner end of the channel-lever and the face 66 of the bit from the grinding wheel so that the face 66 is spaced therefrom,-when the outer end of the channellever is swung upwardly, and the face 66 moved downwardly in proximity to the lower end of the grinding wheel 2|. It is thus seen that the face 66 engages with the grinding wheel when swinging upwardly for a portion of its travel, but does not engage with the grinding wheel when swinging downwardly to the starting lowermost position. The grindingaction therefore occurs upon the upward swinging movements of the face 66 and there are time intervals between these upward movements which permit the face .66 to cool so that the drill will not burn. As the face 66 is being ground, .the drill is advanced longitudinally toward the grinding wheel by moving the carriage or slide 40 forwardly, which is caused by turning the feed screw 46. When the channel-lever 61 has its outer end in the uppermost position and swung to the right, the face 66 will engage the periphery of the grinding wheel, at the selected angle to determine the general radial angle of the far; 66 and the periphery of the grinding wheel will hollow grind the face 66 or render the same concave, as more clearly shown in Figure 8. After one face 66 is ground, the bit is turned upon its longitudinal axis and clamped within the channel-lever to grind the other face 66 It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape, size, and arrangement of parts, may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims.

' Having thus described the invention, what I claim is:

V l. A machine :for grinding a bit or the like, comprising a support, a motor mounted upon the support and having its armature shaft arranged substantially vertically, a substantially horizontally rotating grinding wheel mounted upon the uppermost the armature shaft, a substantially vertical post mounted upon the support and adapted to be turned upon its longitudinal axis, a substantially horizontal carriage mounted upon the post and movable with relation thereto toward the grinding wheel, means to move the carriage, a member, means pivotally connecting the member and carriage and extending transversely of the carriage, a carrier, a pivot element connecting the carrier and member and extending at substantially a right angle to the pivotal connecting means, the arrangement being such that the carrier may be swung longitudinally and transversely of the carriage, adjustable means to regulate the extent of longitudinal swinging movement of the carrier toward the grinding wheel, and a bit holding device mounted upon the carrier and arranged to bring the face of the bit into engagement with the periphery of the grinding Wheel.

2. A machine for grinding a bit or the like, comprising, a support, a motor mounted upon the support and having its armature shaft substantially vertical, a grinding wheel mounted upon the armature shaft to rotate substantially horizontally, a substantially vertical post arranged near the grinding wheel, a substantially horizontal carriage mounted upon the post and movable toward the grinding wheel, said carriage having a transverse opening, means to move the carriage, a member having a shank pivotally mounted within the transverse opening, the member being arranged upon one side of the carriage, a carrier mounted upon the member, a pin pivotally connecting the carrier and member and disposed at substantially a right angle to the shank, a tail carried by the outer end of the carrier, an adjustable stop for the tail mounted upon the carriage, and means mounted upon the carrier for holding a bit and arranging the bit 1ongitudinally of the carrier and bringing its face into engagement with the periphery of the grinding wheel.

3. A machine for grinding a bit or the like, an upstanding post, a motor holding frame mounted upon the post and including a horizontal bar and vertical arms and a curved strap which is concentric with the post, a motor mounted within the frame and having the curved strap secured thereto, the motor having its armature shaft vertical, an arm mounted upon the post, a vertical post mounted upon the arm, a carrier, means to pivotally mount the carrier upon the vertical post so that the carrier can swing in vertical and horizontal planes, and a bit holding device mounted upon the carrier.

4. In a machine for grinding a bit or the like, a grinding wheel having a periphery, means to rotate the grinding wheel, a post extending parallel with the axis of rotation of the grinding wheel and arranged radially outwardly of the grinding wheel, the post being adapted to be turned upon its longitudinal axis, means to clamp the post in the selected adjusted position, a carriage mounted upon the post and shiftable toward the periphery of the grinding wheel, a bit holding device including a handle, a pivot for the bit holding device mounted upon the carriage and arranged between the ends of such device whereby the handle extends beyond the pivot for a substantial distance to be grasped in the hand, said pivot being parallel with the plane of rotation of the grinding wheel and arranged generally within such plane of rotation so that the bit holding device may have its end next to the grinding wheel swung longitudinally of the axis of rotation of the grinding wheel while the bit is engaging the periphery to effect the grinding action, and a second pivot element carried by the first pivot element and engaging the bit holding device, the second pivot element being arranged at a right angle to the first pivot element and extending generally parallel with the axis of rotation of the grinding wheel, the bit holding device swinging upon the second pivot to shift its end next to the grinding wheel generally radially with respect to the grinding wheel, the arrangement being such that the bit is hollow ground.

5. In a machine for grinding a bit or the like, a grinding wheel having a periphery, means to rotate the grinding wheel, a post extending parallel with the axis of rotation of the grinding Wheel and arranged radially outwardly of the grinding wheel, said post being adapted to be turned upon its longitudinal axis, means to indicate the extent of turning movement of the post, means to clamp the post in the adjusted selected position, an elongated carriage mounted upon the post to be shifted longitudinally toward the periphery of the grinding wheel in a plane parallel with the plane of rotation of the grinding wheel, adjustable means to shift the carriage longitudinally and hold it in the selected adjusted position, a pin arranged parallel with the plane of rotation of the grinding wheel and extending transversely of the carriage and pivotally mounted upon the carriage, a second pin carried by the first pin and adapted to be arranged generally parallel with the axis of rotation of the grinding wheel, the first named pin being arranged generally in the plane of rotation of the grinding wheel, a carrier pivotally mounted upon the second pin, a lever mounted upon the carrier and having the first pin arranged between its ends so that the rear end of the lever extends beyond the first pin for a substantial distance to be grasped in the hand, and a bit holding device mounted upon the forward end of the lever for holding a bit in a position extending longitudinally of the lever, the arrangement being such that the lever may be turned about the axis of the first named pin and the bit moved longitudinally of the axis of rotation of the grinding wheel while the bit is engaging th periphery of the grinding wheel to effect the grinding action.

FATE DIXON. 

